He is noted for having contested from almost every major party of his time and has the record for the longest speech in parliament, lasting thirteen and half hours.

He was born as a twin in Dangedera, Richmond Hill, Galle and was named Don Wijeyananda Dahanayake after the Wijayananda Pirivena.

His father was Don Dionesius Panditha Sepala Dahanayake, was a Muhandiram, who later served as the Kackckeri Mudliyar of Galle and was a scholar in oriental languages.

In addition he coached the college athletics and the junior cricket teams and organized the English Literary Union and the Debating Society.

As a member of the Trotskyite Lanka Sama Samaja Party, he was elected to the Galle Municipal Council from the Kumbalwella Ward, which he held until 1944.

[3] In 1947, he was only one of three members who voted against the Soulbury Constitution which enabled self rule for Ceylon as an independent Dominion inside the British Commonwealth.

With a campaign in which he did not spend any money, he won against the wealthy H. W. Amarasuriya contesting from the United National Party and was elected to the House of Representatives.

[4] In 1955, he gave leadership to the nationalist movement that sort for "Sinhala only" under a new party called the "Basha Peramuna" (Language Front) which aligned with the alliance Mahajana Eksath Peramuna (Peoples United Front) led by S. W. R. D. Bandaranaike which contested the 1956 general elections and won a landslide victory against the ruling United National Party which was reduced to eight seats in parliament.

[4] In 1959, he became the acting leader of the house after the incumbent C. P. de Silva was taken to London for medical treatment after becoming ill after consuming a glass of milk at a cabinet meeting.

Bandaranaike was assassinated on 26 September 1959 and with the letter as a reference, Sir Oliver Goonetilleke, the Governor General of Ceylon appointed Dahanayake as Prime Minister.

The situation deteriorated under Dahanayake, which was compounded by the investigation into the assassination which drew suspicion on several ministers and resulted their resignation or removal.

Dahanayake made a sudden request to the Governor-General of Ceylon for the dissolution of parliament on 5 December 1959 calling for fresh elections.

He formed Lanka Prajathanthravadi Pakshaya (Ceylon Democratic Party) from which he contested the March 1960 general elections from Galle which he lost to W. D. S. Abeygoonawardena by 400 votes.

He resigned from United National Party and sat as an independent after his request for a free vote for the republican constitution was refused.

Dahanayake gained the seat in the following by-election as the candidate from the United National Party with a majority of 13,012 votes and sat as a backbencher.

When appointed Prime Minister, he moved into Temple Trees carrying his own things in two old suitcases from his room in the Srawasthi Mandiraya.

When he resigned from the post of prime minister following his electoral defeat, he packed his personal belongings to the same suitcase left Temple Trees to Galle.